while python read from file

Question

Here is my code:

variables = [0, 0, 0, 0]

while (variables[2]<4):
    with open('vystup_online.txt') as f:
        for line in f:
            variables = (line.strip().split())
    print variables[2]

and here's my .txt file:

2 10.249402 0.000000 25.596176

I was assuming it will print variables[2] until I change the file to:

2 10.249402 1.000000 25.596176

or similar.

I am just getting

>>>
0.000000

and nothing more. What's wrong?

This is what I need:

What are you actually trying to do? Do you want to watch a file for changes? This sounds somewhat like an [XY Problem](http://meta.stackexchange.com/questions/66377/what-is-the-xy-problem). — thegrinner, May 12 '14 at 14:00

score 1 · Accepted Answer · edited May 23 '17 at 12:21

1

variables[2]<4 will always be False at the second iteration.

since variables[2] is a string after the line variables = (line.strip().split()) and 4 is an int

and in python 2.x while string < int will result as False

you can read more about your mistake here

edited May 23 '17 at 12:21

Community

1
1

answered May 12 '14 at 14:02

Kobi K

7,743
6
42
86

sure...didn't notice that. It should look like this: `while (float(variables[2])<4):` now it works. – TomasJ May 12 '14 at 14:07

score 1 · Answer 2 · answered May 12 '14 at 14:02

1

variables[2] is a string. '0.000000' < 4 is false.

answered May 12 '14 at 14:02

njzk2

38,969
7
69
107

while python read from file

2 Answers2